bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2022, Volume and Issue: unknown

Published: Aug. 25, 2022

Abstract Background Non-cyanobacteria diazotrophs (NCDs) were shown to dominate in surface waters shifting the long-held paradigm of cyanobacteria dominance and raising fundamental questions on how these putative heterotrophic bacteria thrive sunlit oceans. The absence laboratory cultures significantly limits our ability understand their behavior natural environments and, consequently, contribution marine nitrogen cycle. Results Here, we used a multidisciplinary approach report an unprecedented finding diatom Phaeodactylum tricornutum ( Pt ) NCDs phycosphere or pelagic community sustaining its survival bioavailable nitrogen. We sequenced bacterial metacommunity associated with assembled several genomes, identifying multiple from Rhizobiales order, including Bradyrhizobium , Mesorhizobium Georhizobium Methylobacterium . demonstrated nitrogen-fixing PtNCDs through silico identification fixation genes, by using PCR, acetylene reduction, 15N incorporation. showed wide occurrence this type interactions isolation other microalgae, environment, predicted associations photosynthetic microalgae. Conclusions Our study underscores importance microalgae permit support fixation. This work provides unique model Pt-NCDs ecology interaction advancing understanding key drivers global

Language: Английский